The specific objective of the present research is to apply investigate techniques developed during the past three years to a large population (normals, ocular hypertensives, glaucoma suspects and individuals with definite glaucomatous disease) for a sufficient duration that spontaneously occurring changes will be documented. The techniques include fine resolution, rapid sequence photography of the transit of fluorescein through the eye, semiquantitative description and stereoscopic photography of the optic nerve and correlaion by means of a computer program of standard information such as intraocular pressure, nature of the visual field and ophthalmic artery pressures. Approximately 300 cases with high quality angiograms have already been entered into a study supported by the NIH in the recent past. Since glaucomatous deterioration usually takes years to become manifest few cases have changed significantly during the two years that followed mastering the technical problems. The immediate goal is to study for at least two additional years cases defined in the previous investigation as appropriate subjects. It is hoped that the descriptive indicators so developed 1.) will be valid signs of the presence of glaucomatous disease and 2.) perhaps may even be accurate predictors of the future clinical course. If it becomes feasible to subdivide glaucoma cases in terms of basic pathological processes therapy may become more rational and effective, thus reducing visual loss caused by glaucoma. A tentative classification might be 1.) ischemia of a particular vessel system, 2.) direct mechanical interference with neural function, 3.) a combination of ischemia plus mechanical abnormality.